Formation of tropical forests needs mean annual temperature and mean annual precipitation:
A) $18 - {25^ \circ }C$ and $150 - 400cm$
B) $5 - {15^ \circ }C$ and $50 - 100cm$
C) $30 - {50^ \circ }C$ and $100 - 150cm$
D) $5 - {15^ \circ }C$ and $100 - 200cm$

Hint: Temperature and precipitation are two climatic factors that play an important role in the geographical distribution of forest.

Complete step by step answer:
As we go from equator to pole, temperature decreases. The temperature at the equator is about ${31^ \circ }C$ so the temperature at the tropical region will be less than that and that is $18 - {25^ \circ }C$ and precipitation there is, $150 - 400cm$.
So, the correct answer is option (A).

Additional information:
Species diversity decreases from equator to pole. India has most of its land under tropical latitude and hence it is very rich in diversity of species. It harbors about 1,200 species of birds, nearly 45,000 species of plants. It is said that forests located in tropical regions (like Equador) have about 10 times more diversity than the forest of equal area present in the temperate region (like Midwest of USA). The largest rainforest, the Amazon rainforest is also present in the tropical regions (South America). It is the habitat of more than 40,000 species of plant, 3,000 fishes, 1,300 birds, 427 mammals, and more than 1,25,000 species of invertebrates and many more are still to be discovered.

Note: The reason behind the more diversified tropical forest than the temperate forest is estimated that, in the past, temperate forests were subjected to continuous change while tropical regions remained undisturbed for millions of years and hence it provides a long time for the evolution of different species.