$$sec^4 θ - sec^2 θ$$ is equal to

$$sec^4 θ - sec^2θ$$ = $$\frac{1}{cos^4 θ} - \frac{1}{cos^2 θ}$$

$$\frac{1}{cos^4θ} - \frac{1}{cos^2θ}$$= $$\frac{1 - cos^2θ}{cos^4θ}$$

$$\frac{1 - cos^2θ}{cos^4θ} = \frac{sin^2θ}{cos^4θ}$$

$$ \frac{sin^2θ}{cos^4θ} = tan^2θ \times sec^2θ $$

$$ tan^2θ \times sec^2θ $$ = $$tan^2 θ \times $$ $$ (tan^2 +1)$$

$$tan^2 θ \times $$ $$ (tan^2 +1)$$ = $$tan^2 θ + tan^4 θ $$

Hence Option B is the correct answer.