Directions: For the Assertion (A) and Reason (R) given below, choose the correct alternative. Assertion (A): Cut fruits and vegetables should not be kept in the open for long. Reason (R): Their vitamin content gets ruined on exposure for a long time.

Introduction / Context:
This question tests basic ideas of food science and hygiene. It asks why it is not advisable to leave cut fruits and vegetables exposed for a long duration. The reason mentions loss of vitamins, which is an important nutritional concern, particularly for vitamins that are sensitive to air and light.

Given Data / Assumptions:

• Assertion (A): Cut fruits and vegetables should not be kept in the open for long.
• Reason (R): Their vitamin content gets ruined on exposure for a long time.
• We assume school level understanding of nutrition and food handling.
• The goal is to check whether A and R are true and whether R explains A.

Concept / Approach:
Once fruits and vegetables are cut, more surface area is exposed to air, light and microorganisms. Some vitamins, especially vitamin C and some B group vitamins, are sensitive to oxidation and degrade with prolonged exposure. At the same time, open exposure can allow microbial growth and spoilage. The reason focuses on the nutritional loss part of the problem.

Step-by-Step Solution:
Step 1: Evaluate Assertion (A). It is standard advice in nutrition and hygiene that cut fruits and vegetables should be eaten soon after cutting or kept covered and refrigerated if they must be stored. Leaving them in the open for long is discouraged. So A is true.Step 2: Evaluate Reason (R). Many vitamins are unstable when exposed to air and light. Vitamin C is a well known example; it is easily oxidised and can be lost when fruit or vegetable pieces are kept exposed for long periods. Thus it is correct to say that their vitamin content gets damaged or reduced by long exposure.Step 3: Check whether R explains A. One major reason for the advice in A is to preserve the nutritional value of the food, including vitamins. Keeping cut produce exposed for a long time leads to vitamin loss, so avoiding such exposure helps in retaining vitamins. This is a direct explanation of why we should not keep them open for long.Step 4: Therefore both A and R are true, and R can be considered the correct explanation of A, even though in real life there are additional concerns like contamination and spoilage, which further strengthen the advice.

Verification / Alternative check:
Practical experience supports this reasoning: juice, salads or cut fruits taste and look fresher when consumed quickly. Nutrition education materials commonly warn that long exposure reduces vitamin content. If the primary concern were something completely different, such as taste alone, the reason would not match. Instead, textbooks do emphasise nutrient loss for such cases, confirming that R is aligned with A.

Why Other Options Are Wrong:
Option b suggests that R is not the explanation, which is not correct, because vitamin loss is one of the main reasons for the advice. Options c and d imply that one of the statements is false, which conflicts with well accepted nutritional science and good kitchen practice.

Common Pitfalls:
Students may think only about microbial spoilage and forget nutrient loss, or may consider loss of vitamins as a minor detail. However, assertion–reason questions can focus on any one important aspect, and here the author has chosen vitamin damage as the key explanatory point. It is important to recognise that more than one valid reason might exist, but the given reason is still true and relevant.

Final Answer:
The correct evaluation is that both Assertion (A) and Reason (R) are true and R is the correct explanation of A.