Mango trees do not and cannot grow in temperate regions. The most important environment factor responsible for it.
A. Soil
B. Temperature
C. Water
D. Light

Hint: A mango is a stone fruit produced from numerous species of tropical trees belonging to the flowering plant genus Mangifera.
Most of these species are found in nature as wild mangoes.
Mangoes are native to South Asia from where the "common mango" or "Indian mango", Mangifera indica, has been distributed worldwide to become one of the most widely cultivated fruits in the tropics.

Complete answer:
All the plants have their own favourable habitat. Some grow favourably in cold weather and some grow in hot weather.
Some plants have the capability to adjust according to the habitat they are grown in.
Mango is a tropical region fruit.
It favourably grows below 40 degrees fahrenheit.
These are large trees with deep long roots.
Mango trees have the capability to grow in almost any soil.
Mango trees are evergreen hence water availability variations can be seen.
Mango trees have been seen to survive floods as well.
The mature mango trees are seen to survive temperatures up to 25 degrees.
In countries like Canada and Germany the temperature is low. Hence the mango seed is unable to pop out.
The enzymes have a major role in controlling the changes in the plants.
Temperature has a direct effect on the functioning of enzymes.
It controls the basic metabolic activity.
This is the reason mango trees are not able to grow in temperate regions.
Hence temperature has a major role in growth of mango plants.

The correct answer is B ie temperature.

Note: Mango trees have been seen to withstand hard weather conditions like floods.
The adult mango trees are believed to withstand temperatures up to 25 degrees.
Mango trees have the capability to grow in any type of soil.
Hence soil, water and light do not have a significant role in the plant growth as compared to temperature.