In one of Mendel’s experiments, tall pea plants with purple flowers were crossed with dwarf plants with white flowers. The flowers of all the plants of his praise were purple in color. But about half of them were dwarfs. From this it can be said that the genetic composition of tall parent plants was :

(a) TTWW                          (b) TTww

(c) Tt WW                          (d) Tt Ww