Step 1: Fact
Omega-3 fatty acids (found in fish oil and flax) raise HDL, the good cholesterol, and lower triglycerides.
Step 2: Others
Trans fats raise LDL and lower HDL. Omega-6 does not specifically raise HDL. Cis fats as a general category do not raise HDL in this sense.
Final Answer:
Omega-3 fatty acids raise HDL.
\[ \boxed{\text{(B)}\ \text{Omega-3 fatty acids}} \]