In this exercise, 'a' is the best option, but isn't 'b' quite a right one too?

Hi TS! A seems very obvious to me. B could be the reason they decided to make a change, but "want" doesn't mean that's what you "decide". "Choose" is a good synonym for "decide". They chose to change their lives. I think C should be: they did not have much choice but to change their lives (they had to change their lives).

Hi Shawn,
Thank you for your reply.
Will it be better like this?
Circle the letter that best completes the sentence.
Joseph and Whitney decided to make a change in their lives means
a. they chose to change their lives.
b. they wanted to have a different life.
c. they did not have much

As strange as it might hit you, C is the answer.

Hi screamerer,
Thank you for your reply.
My 'C' or Shawn's 'C'?

TS

Yours, just the way it came in the original excercise:

"they did not have much choice to change their lives".

Hi screamerer,
Thank you for your reply.
Then I should change it to Shawn's, "They did not have much choice but to change their lives (they had to change their lives), shouldn't I?
Only one option can be correct.

TS

No, you shouldn't. It's as it should be:

"they did not have much choice to change their lives".

See, to make a change in your life is not the same as having a different life, so neither a nor b is the correct answer. c, on the other hand, is very acceptable as taken to be the reason why Joseph and Whitney decided to make a change i

Hi screamerer,
Wow! Thank you for you help.

TS

Hi again TS, you're welcome.

I would be cautious with advice from non-native speakers.

If by "they did not have m

Screamerer, I like some of your reasoning, since it's true that "changing one's life" could mean completely/totally, but even making a small change in one's life is changing one's life to some degree.

ScreamererThey couldn't change their lives, so they decided to make a change in them.

Good point, I might have misunderstood C.