Answer :

To determine which region has the highest population growth rate, let's carefully analyze the options provided. Generally, we need to understand some global demographic trends which can be highlighted by looking into population growth rates globally.

1. Africa: Africa has been experiencing high population growth rates due to factors such as higher fertility rates and improvements in healthcare which have decreased infant mortality rates.

2. India: India also has a significant population growth, but it has been slowing down in recent years due to increased access to family planning and education.

3. China: China, on the other hand, has seen a dramatic decline in population growth rate due to policies like the one-child policy (which has been relaxed in recent years), and the current demographic trends point towards an aging population.

4. Europe: Europe, generally speaking, has very low or even negative population growth rates in many countries due to low birth rates and aging populations.

Given these general understandings, it is apparent that Africa has the highest population growth rate among the regions listed.

The correct answer to the question "Which region has the highest population growth rate?" is:

Africa