An Ideal Carnot Engine Operating Between a Warm Reservoir of Unknown

Multiple Choice

An ideal Carnot engine operating between a warm reservoir of unknown temperature and a cold reservoir at $1.76 \mathrm {~K}$ has an efficiency of $11.0 \%$ What is the temperature of the warm reservoir?

A) 1.98 K
B) 0.180 K
C) 157 K
D) 0.160 K