Because of less availability and greater demand for scientif

[BTGmoderatorAT]

Because of less availability and greater demand for scientific research, platinum remains consistently expensive, like gold.

(A) Because of less availability and greater demand for scientific research, platinum remains consistently expensive, like gold.
(B) Because of less availability and increased demand for scientific research, platinum remains consistently expensive, like that of gold.
(C) Because of decreased availability and increased demand in scientific research, platinum remains expensive, like gold.
(D) Because of decreased availability and increased demand for scientific research, platinum remains expensive, like gold.
(E) Because of decreased availability and greater demand in scientific research, platinum remains at a consistently high price, like that of gold.

I'm confused between C and D. Can any experts help?

[Vincen]

I think option C is correct, but I'd like an explanation from the experts. We'd wait for you experts.