Step 1: Analyzing the sentence.
The sentence given is "Deepu studies since 7 a.m. to 9 a.m. daily." The word "since" is used to indicate the starting point of an action or event in the past.
Step 2: Identifying the error.
The phrase "since 7 a.m." is incorrect because "since" is used with a point in time that indicates the start of an ongoing action. When referring to a specific duration, the correct word to use is "from." The phrase should be "from 7 a.m. to 9 a.m."
Step 3: Conclusion.
The word **since** is incorrect in this sentence. The correct phrase should be "from 7 a.m. to 9 a.m."
Final Answer: \[ \boxed{\text{The correct answer is (C) since.}} \]
Fill in the blank with the correct option:
She has been working here __________ five years.