Note: Since all the options involve the trigonometric ratios sec θ and tan θ, so we divide the whole term (numerator as well as denominator) by cos θ.

To find:

Consider

Dividing numerator and denominator by cos θ, we get

Rationalizing the term by multiplying it by ,

Now, as 1 + tan² θ = sec² θ

⇒ sec² θ – tan² θ = 1