An extreme shortage of food for a long period of time which leads to widespread hunger and malnutrition in a given population is called food crisis.
There are various reasons for a food crisis. Some of these reasons are as follows:
Change in climate - Global warming and climate change over the years has lead to droughts, floods, and untimely rains which have caused huge effects on food production. So, option B is correct.
Improper storage - Improper storage facilities leads to wastage of produce. Proper facilities like cold storage and seed drying facilities are needed to prevent spoiling of food and also to protect it from rodents and insects. So, option A is correct.
Improper transport and distribution of food - Proper transport of food is another major challenge. This has led to overly fed populations in few countries and less fed populations in some other countries. Many grocery stores in the USA dump the surplus products in the waste bins because transporting them is even more costly. Therefore, option c is incorrect.
Improper agricultural management - Insufficient tilling of land, inappropriate irrigation and lack of timely caring of the field and crop before, during and after crop raising leads to insufficient and poor quality produce. So, option D is correct.