Which is the best response?

[ngoc_lan]

- Do you know how old am I?
- ___________.
a. I couldn't help it.
b. Happy birthday.
c. Don't mention it.
d. I haven't a clue.

Does the speaker of the first sentence mean anything else apart from asking the other if he knows his age?
I'll choose d but I'm not sure. If d is correct, can I say "I haven't a clue" instead of " I haven't got a clue" or "I don't have a clue"? Is it OK if I use it in my essay or speak to others?
I hope to receive help from you. Thanks.
ngoc_lan.

[bhaisahab]

- Do you know how old am I?
- ___________.
a. I couldn't help it.
b. Happy birthday.
c. Don't mention it.
d. I haven't a clue.

Does the speaker of the first sentence mean anything else apart from asking the other if he knows his age?
I'll choose d but I'm not sure. If d is correct, can I say "I haven't a clue" instead of " I haven't got a clue" or "I don't have a clue"? Is it OK if I use it in my essay or speak to others?
I hope to receive help from you. Thanks.
ngoc_lan.

d is correct. Yes, you can use it.

[BobSmith]

Do you know how old am I?

Does the speaker of the first sentence mean anything else apart from asking the other if he knows his age?

[not a teacher]

No, there is not hidden meaning here. With context, there can be lots of subtext.

[ngoc_lan]

Thanks a lot!