Question

Change the underlined phrase into a clause in the sentence given below:
While having my green tea, I felt energized .

• A. NO CHANGE
• B. While I had my green tea
• C. Therefore I had my green tea
• D. Because having had my green tea

Answer 1

The correct option is B While I had my green tea

An adverb clause is a group of words containing a subject and a verb, and it functions as an adverb, by modifying an adjective, verb or an adverb. Adverb clauses generally begin with a subordinate conjunction (since, because, while, etc.)
Generally, while expanding an adverb phrase to a clause, the subject is added and the present participle (verb + ing) is changed into a verb. (If there is an auxiliary/helping verb required, it is added.)
The underlined words form a phrase, it has no subject. Hence the sentence needs to be changed and option A is incorrect.
Option B is correct because the subject "I" is added and the verb "had" replaces the present participle.
Option C is incorrect because it is a coordinate clause, whereas an adverb clause is subordinate.
Option D is incorrect as "because" is an adverb of reason, whereas the adverb here pertains to time.