Lacking information about energy use, people tend to overestimate the amount of energy used by
equipment. such as lights, that are visible and must be turned on and off and underestimate that used by
unobtrusive equipment, such as water heaters.
(A) equipment, such as lights, that are visible and must be turned on and off and underestimate that
(B) equipment, such as lights, that are visible and must be turned on and off and underestimate it when
(C) equipment, such as lights, that is visible and must be turned on and off and underestimate it when
(D) visible equipment, such as lights, that must be turned on and off and underestimate that
(E) visible equipment, such as lights, that must be turned on and off and underestimate it when

OA is D
Question : in D , visible equipment, such as lights, that must be turned on and off and underestimate that , what are the two bold thats referring to ?