The line in which one adverb modifies another.
Beautiful orchids can grow very successfully indoors.
Explanation:
An adverb is, to simply speak a verb that functions like an adjective. None of the above sentences except for the one that is selected here contains two adverbs which automatically gets them apart from the correct option as the question requires the existence of two.
The two adverbs here are the adverbs 'very' and 'successfully.'
The adverb 'very' is able to modify the adverb that comes after it giving it a superlative.
