I . . . . . . . . this book since morning. A. had been reading B. has been reading C. have had read D. shall be reading

The correct answer is: B. has been reading

The verb “to read” is an activity that takes place over time. In this sentence, the time frame is “since morning.” This means that the activity of reading has been going on for a period of time that began in the morning. The only verb in the list that expresses this meaning is “has been reading.”

The other verbs do not express the meaning of an activity that has been going on for a period of time.

• “Had been reading” expresses an activity that began in the past and continued up to a point in the past. In this sentence, there is no indication of a point in the past when the activity of reading stopped.
• “Have had read” expresses an activity that began in the past and is still going on in the present. In this sentence, there is no indication that the activity of reading is still going on.
• “Shall be reading” expresses an activity that will begin in the future. In this sentence, there is no indication that the activity of reading will begin in the future.