The correct option is C more industrious
The sentence is said to be in the comparative degree when two nouns are compared, one noun is of a higher degree compared to the other. Here the noun 'Jerry' is 'more industrious' than the other noun 'brother'. Option C is correct because the adjective has three syllables while forming the comparative we do not add the suffix '-er' to it. Instead, 'more' precedes the adjective. Option A is incorrect, the adjective has three syllables and hence the suffix '-er' is not added to it. Option B is incorrect because the phrase in it is of the positive degree. Option D is incorrect because 'very' isn't a comparative, nor is it used in any degree of comparison.