Select the most appropriate option to fill in the blank and make a grammatically correct sentence.

I was determined not to stay in hospital for any longer ____ was strictly necessary.

than

The most appropriate option to fill in the blank and make a grammatically correct sentence is:

☀ than

The sentence would read: "I was determined not to stay in hospital for any longer than was strictly necessary."

Explanation: "Than" is used in comparisons to indicate a limit or extent. In this context, it's used to compare the length of stay in the hospital with what is strictly necessary. The other options don't fit the context:

• When: This doesn't convey a comparison of duration.

• Then: This doesn't convey a comparison of duration.

• That: This doesn't convey a comparison of duration.