Consider the sets `phi, A = { 1, 3 }, B = {1, 5, 9}, C = {1, 3, 5, 7, 9}`.
Insert the symbol ⊂ or ⊄ between each of the following pair of sets:
(i) `phi` . . . B
(ii) A . . . B
(iii) A . . . C
(iv) B . . . C

Explanation

To solve the problem, we need to determine the subset relationships between the given sets: φ (the empty set), A, B, and C.

Let's analyze each pair step by step.

### Step 1: Analyze φ and B
- **Set φ**: The empty set contains no elements.
- **Set B**: B = {1, 5, 9}

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