Lightweight Nature of Plastics
Plastics are significantly lighter than metals, making them an ideal choice for aircraft and spacecraft construction. This weight reduction helps in improving fuel efficiency and overall performance of the vehicles.

Cost-effectiveness
Plastics are generally cheaper than metals, which can help in reducing the overall cost of manufacturing aircraft and spacecraft. This cost-effectiveness is beneficial for the aerospace industry, especially when producing large quantities of components.

Easy Handling
Plastics are easier to handle and shape compared to metals. They can be molded into complex shapes and designs, allowing for greater design flexibility in the construction of aircraft and spacecraft. This ease of handling also contributes to faster production times.

Recyclability of Plastics
Plastics can be recycled, which is important for sustainability in the aerospace industry. By using recyclable plastics in the construction of aircraft and spacecraft, manufacturers can reduce their environmental impact and promote a more sustainable approach to production.
In conclusion, the use of plastics in aircraft and spacecraft is driven by their lightweight nature, cost-effectiveness, ease of handling, and recyclability. These factors make plastics a preferred material choice for various components in the aerospace industry, contributing to improved performance, reduced costs, and environmental sustainability.

I think option (a)