Option 1 states that both statements are individually true and that Statement II is the correct explanation of Statement I. Statement I says that pressure gradients determine the velocity of winds, which is generally true. When there is a difference in pressure between two areas, air will flow from the area of high pressure to the area of low pressure, resulting in wind. However, Statement II claims that when isobars (lines of equal atmospheric pressure) are closely spaced, the wind velocity would be gentle, which is false. In reality, when isobars are closely spaced, it indicates a stronger pressure gradient and results in stronger winds, not gentle ones. Therefore, Option 1 is incorrect.

Option 2 states that both statements are individually true, but Statement II is not the correct explanation of Statement I. As explained earlier, Statement II is indeed false, so Option 2 is incorrect.

Option 3 states that Statement I is true, but Statement II is false. This is the correct answer as Statement I is generally true, and Statement II is false, as explained above.

Option 4 states that Statement I is false but Statement II is true. However, this is not the case, as Statement I is generally true, and Statement II is false. Therefore, Option 4