For each tuple r in R do

For each tuple s in S do

If r and s satisfy the join condition then output the tuple <r,s>

This algorithm will involve Nr*Bs+Br block transfers and Nr+Br seeks, where Br and Bs are

number of blocks in relations R and S respectively and Nr is number of tuple in relation R.

Now to have less block accesses, Nr should be less and it is already given that |R|<|S|. Relation

r(R) should be in the outer loop to have fewer number of disk block accesses.

So Answer is A.

I have copied this answer from GATEForum solutions, Please someone verify and explain this answer?