To answer this question, we need to know about Mahatma Gandhi's family and his children. Let's go through each option to determine the correct answer:
Option A) Only child - This option is incorrect because Mahatma Gandhi had more than one child.
Option B) Second child - This option is incorrect because Mahatma Gandhi had more than two children.
Option C) Eldest child - This option is incorrect because Mahatma Gandhi had children older than Devdas.
Option D) Youngest child - This option is correct because Devdas was the youngest child of Mahatma Gandhi.
The correct answer is D) Youngest child. Devdas was Mahatma Gandhi's youngest child.