When the tension on wire is 4 units, its length is l1 and when the tension is 5 units, its length is l2 . Its natural length is

Q: When the tension on wire is 4 units, its length is l₁ and when the tension is 5 units, its length is l₂ . Its natural length is

(a) 4l₁ – 3l₂

(b) 5 l₁ – 4l₂

(c) 5l₂ – 4 l₁

(d) (l₁ + l₂)/2