What openssl command will generate a private RSA key of 2048 bits and no passphrase?

A.
openssl genrsa des3 out privkey.pem 2048

B.
openssl genrsa out privkey.pem 2048

C.
openssl genrsa nopass out privkey.pem 2048

D.
openssl genrsa nopass des3 out privkey.pem 2048