Which digital signature has she chosen?

Shayla is designing a web-based application that will pass data to and from a company extranet.
This data is very sensitive and must be protected at all costs. Shayla will use a digital certificate
and a digital signature to protect the data. The digital signature she has chosen to use is based on
the difficulty in computing discrete logarithms. Which digital signature has she chosen?

A.
Rabin

B.
Diffie-Hellman