Step 1: Understand the question:
A departmental store is a big retail shop divided into many departments under one roof, such as clothes, grocery, toys and electronics.
We must check (A), check (R), and see if (R) explains (A).
Step 2: Check Assertion (A):
A departmental store needs a large building, often in the heart of a city, where rent or land cost is high.
It also needs furniture, lifts, air conditioning, a big stock of goods and many trained staff.
All this needs a lot of money, so (A) is TRUE.
Step 3: Check Reason (R):
A departmental store works on a large scale with many departments. It keeps a wide variety of goods under one roof.
So (R) is TRUE.
Step 4: Check the link:
Because the store is large and keeps many kinds of goods, it needs more space, more stock and more staff. That is why the capital needed is heavy.
So (R) is the correct explanation of (A).
Step 5: Why the other options are wrong:
Option (B) says (R) does not explain (A). But large size and variety are the cause of heavy capital.
Options (C) and (D) call one of the statements false. Both are true.
Final Answer:
Both statements are true and (R) explains (A). This is option (A).
\[ \boxed{\text{Option (A): Both (A) and (R) are true, and (R) is the correct explanation of (A)}} \]