Answer:
B. I am sorry to hear your sad news; but if I may be of any help, please do not hesitate to contact me.
Explanation:
The main purpose of a sympathy note is to offer either an emotional support, sense of comfort , or empathy to the victim of the misfortune. Usually given by the people whoa re close to the victim.
The sentence in option B:
I am sorry to hear your sad news; but if I may be of any help, please do not hesitate to contact me
Leans more on offering practical solution to the victim rather than emotional support. This tend to be more appropriate if given by a colleague that knows the victim but does not really close to the victim.