The length of AC is :

1. $(60 - 20\sqrt{3})$ m

2. $60\sqrt{3}$ m

3. $(60 + 20\sqrt{3})$ m

4. $20\sqrt{3}$ m

In rectangle BCDE,

Opposite sides of rectangle are equal.

∴ BE = DC = 60 m

We know that,

tan θ = $\dfrac{\text{Perpendicular}}{\text{Base}}$

From figure,

In △ ABE,

⇒ tan 30° = $\dfrac{AB}{BE}$

⇒ $\dfrac{1}{\sqrt{3}} = \dfrac{AB}{60}$

⇒ AB = $\dfrac{60}{\sqrt{3}} = 20\sqrt{3}$ m.

In △ EBC,

⇒ tan 45° = $\dfrac{BC}{BE}$

⇒ $1 = \dfrac{BC}{60}$

⇒ BC = 60 m.

From figure,

AC = AB + BC = $(20\sqrt{3} + 60)$ m.

Hence, Option 3 is the correct option.