Which statements are correct? (Select all correct options.)

Select all that apply

• Option A

  For a two-converging-lens astronomical telescope, tube length in normal adjustment is the sum of lens focal lengths.

• Option B

  For an astronomical telescope, the tube length for a near-point final image is smaller than for normal adjustment.

• Option C

  For a compound microscope initially producing the final image at infinity, shifting the eyepiece towards a fixed objective by fₑ²/(D + fₑ), with the object fixed, can produce the final image at the near point.

• Option D

  For a compound microscope adjusted to keep the final image at infinity, decreasing tube length always increases objective magnification.