Question

Which pronoun correctly completes this sentence?

Ingrid tells her friends about rugby, and _______ tell her about football.

their
them
they
themselves

Answer 1

The correct pronoun would be they. It is the only one that makes sense. 

Ingrid tells her friends about rugby, and they tell her about football.

These don't make sense:

Ingrid tells her friends about rugby, and their tell her about football.

Ingrid tells her friends about rugby, and them tell her about football.

Ingrid tells her friends about rugby, and themselves tell her about football.

Answer 2

Ingrid tells her friends about rugby, and _______ tell her about football.

The answer is They because

Ingrid tells her friends about rugby, and Their tell her about football.

Ingrid tells her friends about rugby, and Them tell her about football.

Ingrid tells her friends about rugby, and They tell her about football.

Ingrid tells her friends about rugby, and Themselves tell her about football.

Hope this helps.