Correct Answer - Option 4 : 3

**Given:**

For two lines 7x + 3y = 5 and 14x + 2ky = 12 to be parallel

**Concept used:**

For two lines to be parallel, a_{1}/a_{2} should be equal to b_{1}/b_{2}

**Calculation:**

For two lines to be parallel, a_{1}/a_{2} should be equal to b_{1}/b_{2}

For the given set of lines, a_{1} = 14, a_{2} = 28, b_{1} = 6, b_{2} = 4k.

According to the question,

⇒ 14/28 = 6/4k

⇒ k = (3/2) × (28/14)

⇒ k = 3

**∴ The value of k should be 3.**