Answer & explanation
Correct answer: option 1
$\beta_1 = \beta_2$
$\frac{\lambda_1 D_1}{d_1} = \frac{\lambda_2 D_2}{d_2}$
$\frac{D_1}{D_2} = \frac{\lambda_2}{\lambda_1} \frac{d_1}{d_2} = \frac{2}{1} \times \frac{2}{1} = 4:1$
Correct answer: option 1
$\beta_1 = \beta_2$
$\frac{\lambda_1 D_1}{d_1} = \frac{\lambda_2 D_2}{d_2}$
$\frac{D_1}{D_2} = \frac{\lambda_2}{\lambda_1} \frac{d_1}{d_2} = \frac{2}{1} \times \frac{2}{1} = 4:1$