Options – when to exercise the option

Hello,

I am sitting an exam on this Friday…
and reviewing my course notes around the options and collar approach, it is clearly said that I do not exercise Put Option either Call Option if the actual interest rate does not exceed the cap and the floor,
Whereas based on the Exam session (2 Dec 2014) in the 2nd question, the actual int rate is 4.3%, including an increse by 0,5 from 3,8% and having strike price at 4,5%.
Then, the actual cost is lower than the option price. However, the futures price went down to 95,48 so we realized a gain of 2 ticks and exercised the option anyway.

Therefore, the futures price determines actually whetehr to exercise or not ?

Thank you in advance for your advice
Regards
Tomasz Sawa