Select the correct indirect form of the given sentence.

The supervisor said to the staff, "Make sure that every room is disinfected properly."

The supervisor instructed the staff to make sure that every room was disinfected properly.

The correct indirect form of the given sentence is:

The supervisor instructed the staff to make sure that every room was disinfected properly.

The other options are incorrect:

• The supervisor instructed the staff to make sure that every room had been disinfected properly. This is incorrect because the tense of the reported speech is in the past perfect tense, which is used for actions that happened before another action in the past.
• The supervisor instructs the staff to make sure that every room is disinfected properly. This is incorrect because the reporting verb is "instructs", which is used for present tense commands.
• The supervisor instructed the staff to make sure that every room was being disinfected properly." This is incorrect because the tense of the reported speech is in the present progressive tense, which is used for actions that are happening now.