Sentence Correction

While it costs about the same to run nuclear plants as
other types of power plants, it is the fixed costs that
stem from building nuclear plants that makes it more
expensive for them to generate electricity.

(A) While it costs about the same to run nuclear
plants as other types of power plants, it is the
fixed costs that stem from building nuclear
plants that makes it more expensive for them to
generate electricity.

(B) While the cost of running nuclear plants is about
the same as for other types of power plants,
the fixed costs that stem from building nuclear
plants make the electricity they generate more
expensive.

(C) Even though it costs about the same to run
nuclear plants as for other types of power
plants, it is the fixed costs that stem from
building nuclear plants that makes the electricity
they generate more expensive.

(D) It costs about the same to run nuclear plants as
for other types of power plants, whereas the
electricity they generate is more expensive,
stemming from the fixed costs of building
nuclear plants.

(E) The cost of running nuclear plants is about the
same as other types of power plants, but the
electricity they generate is made more
expensive because of the fixed costs stemming
from building nuclear plants.

OA is B ..Please explain..