Step 1: Radish varieties.
Pusa Chetki, an early maturing radish variety, was developed by IARI. Therefore, A corresponds to III.
Step 2: Brinjal varieties.
Pusa Purple Long is a widely cultivated brinjal variety. Thus, B corresponds to I.
Step 3: Tomato varieties.
Pusa Ruby is a popular tomato variety. Hence, C corresponds to II.
Step 4: Pea varieties.
Pusa Pragati is an improved pea variety. Consequently, D corresponds to IV.
Step 5: Conclusion.
The correct matching is A - III, B - I, C - II, D - IV.