Choose the best answer. The combined use of concentrated solar thermal (CST) and fossil fuel energy generation can provide for greatest grid reliability when
(a) CST and fossil fuel plants are built near each other.
(b) fossil fuels are able to be used when CST is unavailable.
(c) CST and fossil fuel energy are equally distributed to the power grid.
(d) fossil fuel plants are built in desert areas where there is consistent sunshine and plenty of open space.
