Question

anxiety for/family members/source of/they are/a /their.​

Answer 1

They are a source of anxiety for their family members.

I am not so sure

Answer 2

Question: anxiety for/family members/source of/they are/a /their.

Answer:

According to the question,

As we know that, in any sentence firstly subject comes then auxiliary verbs comes after that object or any condition comes.

[They are a source of anxiety for their family members.]

Here, "are" is a verb in present tense form which proves that it is in present tense.

This sentence gives us the information of the present time. So, it is in present tense.