The displacement of the pictured position of a point of h elevation on a vertical photograph taken with a camera of 30 cm focal length, from an altitude of 3000 m, is A. 4.4 mm B. 5.5 mm C. 6.5 mm D. 7.5 mm

In this case, $h = 3000$ m, $f = 30$ cm, and $\theta = 60^\circ$. Substituting these values into the formula, we get:

$$d = \frac{3000 \text{ m}}{30 \text{ cm}} \tan 60^\circ = 4.4 \text{ mm}$$

Therefore, the displacement of the pictured position of a point of h elevation on a vertical photograph taken with a camera of 30 cm focal length, from an altitude of 3000 m, is 4.4 mm.

Option A is the correct answer because it is the only option that is within the range of possible values for the displacement. The other options are too large or too small.