38) which of the following is true concerning cancer cells? ; a) they do not exhibit density-dependent inhibition when growing in culture.; b) when they stop dividing, they do so at random points in the cell cycle.; c) they are not subject to cell cycle controls.; d) when they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls.; e) when they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.