Choose the correct answers.
Questions 16-20 are based on the following text.
 

    Bananas belong to the genus Musa (family of Musaceae). The primary purpose of banana cultivation is for the fruit, while some other purposes include fibre production in textile industries and ornamental use.

    Bananas have a wide range of colours such as green, red, and brown, with some seeds in the flesh. Nowadays, people mostly consume sterile yellow bananas because they do not have any seeds. They are cross-bred between green and red bananas. As proven in studies, bananas are good for health since they contain lots of nutritional benefits such as potassium, fibre, and vitamins. Interestingly, bananas can also be cooked before eating. They can also be made into banana flour. Bananas have become an African staple food.

The yellow bananas are sterile because ....