Micro level business environment refers to the specific factors that directly impact an individual business or organization. These factors are typically within the control of the business and can be influenced or managed by the organization.

The correct answer is option 'D' - Customers. Customers play a crucial role in the micro level business environment as they directly impact the success or failure of a business. Understanding customer needs, preferences, and behavior is essential for businesses to develop effective marketing strategies and deliver products or services that meet customer expectations.

Here is a detailed explanation of why customers are considered a micro level business environment factor:

1. Customers as Market Participants:
- Customers are the primary participants in the market since they are the ones who purchase goods or services from businesses.
- Their buying decisions and behavior directly impact the demand for products or services offered by businesses.
- Businesses need to identify their target customers, understand their needs and preferences, and develop products or services that cater to these customer segments.

2. Customer Expectations and Satisfaction:
- Customers have certain expectations regarding the quality, price, convenience, and overall experience associated with a product or service.
- Meeting or exceeding customer expectations is crucial for business success as satisfied customers are more likely to become repeat customers and recommend the business to others.
- Failing to meet customer expectations can lead to negative reviews, reduced customer loyalty, and a decline in sales.

3. Customer Relationship Management:
- Building strong relationships with customers is vital for businesses to retain existing customers and attract new ones.
- Effective customer relationship management involves personalized communication, addressing customer queries and complaints, and providing after-sales support.
- Customer feedback and suggestions are valuable for businesses to improve their products, services, and overall customer experience.

4. Customer Segmentation and Targeting:
- Businesses need to identify different customer segments based on factors such as demographics, psychographics, and behavior.
- By understanding the specific needs and preferences of different customer segments, businesses can tailor their marketing efforts and offerings to effectively target and attract these customers.

In conclusion, customers are an integral part of the micro level business environment. Understanding customer needs, preferences, and behavior is essential for businesses to succeed and thrive in the market. By focusing on building strong customer relationships, meeting customer expectations, and targeting specific customer segments, businesses can gain a competitive edge and achieve long-term success.