Select the option that expresses the given sentence in passive voice.…

The correct answer is Option (4) → A record of every patient’s visit has to be kept by the hospital.

Passive of “has to” + verb:

Change	Active	Passive	Why
Object becomes subject	a record of every patient’s visit	A record of every patient’s visit	The record receives the action, so it becomes the subject.
“Has to” kept	has to keep	has to be kept	“Has to keep” shows a duty now. In the passive it becomes has to be + past participle (V3). “Has” because “a record” is one.
Agent (by ...)	The hospital	by the hospital	The hospital is named, so the doer comes after “by”.
Full sentence	The hospital has to keep a record of every patient’s visit.	A record of every patient’s visit has to be kept by the hospital.

“Ought to” works the same way: ought to + verb → ought to be + V3. Example: You ought to wash the vegetables before cooking. → The vegetables ought to be washed before cooking.

Why the Other Options are Incorrect?

Option 1: A record of every patient’s visit has been kept by the hospital. — Incorrect. “Has been kept” is the present perfect. It says the record is already kept, so the idea of duty in “has to” is lost.

Option 2: A record of every patient’s visit has to keep by the hospital. — Incorrect. The word “be” is missing. Without it, the record becomes the one that keeps something.

Option 3: A record of every patient’s visit had to be kept by the hospital. — Incorrect. “Had to” is the past. The active “has to” is the present.