In the biofortification technique used in modern plant breeding, breeders mainly aim to overcome which type of nutritional problem in human populations?

Introduction / Context:
Biofortification is an important concept in agricultural science and public health. Many people, especially in developing countries, consume enough calories but lack essential micronutrients such as iron, zinc or vitamin A. Plant breeders have developed strategies to increase the nutritional content of crops to address these hidden hunger problems. This question checks whether you understand the main goal of biofortification in plant breeding.

Given Data / Assumptions:

• Biofortification is carried out through conventional breeding or biotechnology methods.
• Target crops include staples such as rice, wheat, maize and sweet potato.
• Problems such as insect pests and plant diseases are addressed by other breeding objectives like resistance breeding.
• The focus here is human nutritional quality, not just crop yield.

Concept / Approach:
Biofortification means improving the nutritional quality of food crops by increasing the content of vitamins and minerals in the edible parts. For example, breeding rice with higher iron and zinc content or sweet potato with higher beta carotene content. This approach aims to combat deficiencies of micronutrients and vitamins in populations that rely heavily on a few staple foods. While pest resistance and disease resistance are important breeding goals, they are not the primary focus of biofortification. Biofortified crops help reduce hidden hunger and associated health problems such as anaemia and impaired immunity.

Step-by-Step Solution:
Step 1: Recall that biofortification is about improving the nutrient content of crops, especially micronutrients. Step 2: Identify micronutrient deficiencies such as lack of iron, zinc and vitamin A as common public health issues. Step 3: Recognise that breeding for insect resistance or disease resistance is usually listed under different breeding goals. Step 4: Compare the options and find the one that specifically mentions deficiencies of micronutrients and vitamins. Step 5: Select the option that matches this description as the correct purpose of biofortification.

Verification / Alternative check:
International programmes such as HarvestPlus and various national agricultural research institutes have developed biofortified varieties like iron rich beans, zinc rich wheat and provitamin A rich maize. Their goal statements explicitly mention reduction of iron deficiency anaemia and vitamin A deficiency in vulnerable populations. Documentation about these programmes confirms that overcoming micronutrient and vitamin deficiencies is the central aim of biofortification, not directly increasing total production or pest control.

Why Other Options Are Wrong:
Option a, loss due to insect pests, is addressed by breeding for insect resistance through different traits such as thicker cuticles, toxins or repellent compounds.

Option b, decrease in food production, refers to yield improvement, which is a classical breeding goal but not the specific definition of biofortification.

Option d, loss due to plant diseases, is handled by disease resistance breeding rather than by increasing micronutrient content.

Common Pitfalls:
Students sometimes think any useful improvement in plant traits through breeding can be labelled biofortification, which is too broad. Another common mistake is to confuse fortification, where nutrients are added during food processing, with biofortification, where nutrient levels are increased directly in the crop. Remembering that biofortification deals with micronutrients and vitamins within the plant itself helps keep the concept clear.

Final Answer:
In biofortification, plant breeders mainly aim to overcome deficiencies of essential micronutrients and vitamins in the diet.