National parties in India are political parties that have a presence and influence across the entire country. These parties play a significant role in the national political landscape and participate in national elections. The correct answer to this question is option 'D', which states that all of the given options (INC, BSP, and BJP) are national parties.

Let's understand each of these parties and why they are considered national parties:

1. Indian National Congress (INC):
- The Indian National Congress is one of the oldest political parties in India and has a rich history. It played a crucial role in India's independence movement and has been a dominant force in Indian politics for many years.
- The INC has a widespread presence across the country and has been able to form governments at the national level multiple times. It has a well-established organizational structure and a significant support base in various states.

2. Bahujan Samaj Party (BSP):
- The Bahujan Samaj Party primarily represents the interests of Dalits (formerly known as untouchables) and other marginalized communities in India. It was founded by Kanshi Ram and is currently led by Mayawati.
- The BSP has a strong presence in the states of Uttar Pradesh and Uttarakhand. While it primarily focuses on regional politics, it has contested national elections and has been recognized as a national party due to its influence and vote share in these elections.

3. Bharatiya Janata Party (BJP):
- The Bharatiya Janata Party is one of the major political parties in India and currently holds power at the national level. It is a right-wing party with a focus on nationalism, Hindutva ideology, and economic reforms.
- The BJP has a widespread presence across the country and has been able to form governments at the center multiple times. It has a strong organizational structure and a significant support base, making it one of the prominent national parties in India.

All three parties, INC, BSP, and BJP, fulfill the criteria of being national parties as they have a wide presence across multiple states, participate in national elections, and have a significant influence on national politics.