Explanation:

Here’s the thing—let’s lay out exactly what’s happening:

- Deepa heads 4 km north from her house.

- Then she turns left (which means now she’s facing west), goes 6 km.

- She turns left again (now heading south), cycles X km, and reaches her school.

- There’s one more clue: Point A is east of the school and 3 km south of her house.

Let’s get visual:

- After moving 4 km north and 6 km west, to get in line with her starting point, she’d need to travel 4 km south. But her real destination (the school) must align with point A, which is 3 km south of her house.

- That means Deepa should travel only 1 km south (since she's already gone up 4 km, and the school is 3 km below the house).

Now, about the options:

- 1 km: That fits—the required southward distance.

- 7 km: That’s if she wanted to go "back" to the starting horizontal line, but not needed here.

- 9 km and 3 km: They don’t fit the clues or the geometry.

So the right answer is

1 km (Option 1)

The reason is simple: School just needs to be 1 km south after the final left turn. All the steps line up around this.