Firstly, I want to congratulate you all. Secondly, I would like to wish you good luck and
For the below question there are three possible answers:

- Firstly, I want to congratulate you all. Secondly, I would like to wish you good luck and ___ I hope you have enjoyed the course.
A) in the end B) at last C) finally

I selected C, is it right?

Question

Firstly, I want to congratulate you all. Secondly, I would like to wish you good luck and
For the below question there are three possible answers:

- Firstly, I want to congratulate you all. Secondly, I would like to wish you good luck and ___  I hope you have enjoyed the course.
 A) in the end     B)  at last              C) finally

I selected C, is it right?

Answer

C is correct, 'finally' applies to the last thing that you say, i.e. you say it near the end of a speech. "Finally, I would like to thank my mother".

A and B apply when you are describing a sequence of events, they apply to the last event in the sequence. "In the end/at last they went to sleep".