Step 1: Apple varieties.
"Red Chief" is a renowned apple variety. Therefore, A corresponds to III.
Step 2: Mango varieties.
"Arka Aruna" is a recognized hybrid mango variety introduced by IIHR, Bengaluru. Thus, B corresponds to I.
Step 3: Ber varieties.
"Illiachi" is a widely known Ber variety. Consequently, C corresponds to II.
Step 4: Pear varieties.
"Bartlett" is a celebrated pear variety. Hence, D corresponds to IV.
Step 5: Conclusion.
The accurate pairing is A - III, B - I, C - II, D - IV.