Step 1: Recall molecular mechanics force fields.
Force fields are mathematical models used in molecular dynamics simulations to calculate molecular energies.
Examples include:
\[
\boxed{
\text{CHARMM, AMBER and GROMOS.}
}
\]
Step 2: Identify the option that is not a force field.
BLAST (Basic Local Alignment Search Tool) is a sequence similarity search program, not a molecular mechanics force field.
Hence,
\[
\boxed{\text{BLAST}}
\]
is the correct answer.
Therefore,
\[
\boxed{(D)}
\]
is the correct answer.