Which of the following Interleukin is raised in a fever?: (A) IFN-γ, (B) TNF-α, (C) IL-10, (D) IL-2
Answer is B. i.e., TNF-α 
“IL-1 and TNF-α are the two most important pyrogens” — Physiology basics.
Pyrogens

Pyrogens are substances that cause fever.
Pyrogens may be exogenous or endogenous

a) Exogenous → Bacterial toxins
b) Endogenous → IL-1, TNF-a, IL-6, Interferons, Ciliary neurotrophic factor

These pyrogens increase the level of PGE2 in the hypothalamus that elevates the thermoregulatory set point and causes fever.