The correct answer is Palakkad.
Palakkad is a district in the state of Kerala, India. It is located in the northern part of the state and is bordered by the districts of Malappuram, Thrissur, and Coimbatore in the state of Tamil Nadu. The district has a population of over 3.5 million people and is the second most populous district in Kerala.
The district is known for its black cotton soil, which is ideal for growing crops such as rice, sugarcane, and tapioca. The district is also home to a number of industries, including textiles, food processing, and engineering.
Palakkad is a popular tourist destination, with a number of historical and cultural attractions. The district is also home to a number of wildlife sanctuaries, including the Eravikulam National Park and the Periyar Tiger Reserve.
The other options are incorrect because:
- Wayanad is known for its coffee plantations.
- Idukki is known for its tea plantations.
- Ernakulam is known for its commercial and industrial activities.