Correct Answer: indolent

Solution : The correct choice is the third option .

Industrious is used to describe someone who is hard-working and diligent.

Indolent is used to describe someone who is lazy and avoids exertion. This makes it the correct antonym for "industrious".

The meanings of the other options are as follows:

• Assiduous is used to describe someone who shows great care and effort.
• Diligent is used to describe someone who is very careful and sincere in his work.
• Productive is used to describe the ability to produce a large amount of something to use.