Salut/Hello!
Step-by-step explanation:
a. The speech you give when convincing a loved one to support you in an important endeavor. -> This seems more like a feeling of comfort needed when you are feeling bad or need emotional/financial support rather than a difference in your life, but if (for example) you have a dream of becoming a doctor, but you don't have the financial support needed to enter a good college/university then the help of a loved one can make a change for your future career.
d. The speech you give when you pitch an important business idea. -> This can make a good, bad or neutral difference in your life, depending on your idea it can be accepted, rejected, or ignored. If it's accepted, you are most likely to be promoted. If rejected or ignored you will be left in the same state with no change.
e. The speech you give that convinces others to vote for a law that affects your everyday life. -> In my opinion this can make a difference in your life because it affects the daily routine or rules you and others.
I didn't see the point of adding c and b because c is for all choices while b is for d and e combined in one answer.
Answer:
c. All of these choices
Why? -> Because the question was "Which speech when delivered effectively, can make a difference in your life?"
Meaning in this situation they are effective (Will 100% be a positive answer) and can make a difference in your life.
I hope it'll be useful! :]