How Has the Hot, X-Ray-Emitting Intergalactic Gas in Galaxy Clusters

Multiple Choice

How has the hot, X-ray-emitting intergalactic gas in galaxy clusters affected the dark matter problem for the clusters?

A) The gas supplies the mass needed to solve the problem, which is now no longer a problem!
B) The gas supplies about 10 times too much mass-now the problem is how clusters so massive are not much more compact.
C) The gas supplies about 2/10 of the dark matter, so with the visible matter, about 7/10 of the mass required to stabilize the cluster is still missing.
D) The gas is very tenuous and supplies almost no mass at all; therefore, it has almost no effect on the dark matter problem.