B. Circulatory, respiratory, nervous
Let's see sentence-by-sentence:
<span>- Objects within the focal length will create real images. --> false
In fact, objects within the focal length create virtual images, as it can be seen in the ray diagrams here:
https://upload.wikimedia.org/wikipedia/commons/4/47/Concavemirror_raydiagram_F.svg
- Concave mirrors converge distant parallel light rays on the focal point. --> TRUE: the parallel rays (with respect to the mirror's axis) are reflected back into the focal point of the mirror, as it can be seen also from the previous picture.
- Concave mirrors can only create real images. --> FALSE: as it can be seen from the first picture, when the object is between the focus and the mirror, its image is virtual.
Concave mirrors can create real and virtual images. --> TRUE: concave mirrors can create real and virtual images, depending on the position of the object.
- Objects far away from concave mirrors will appear enlarged. --> FALSE:
as it can be seen from the ray diagram, the size of the image is smaller than the size of the object. https://upload.wikimedia.org/wikipedia/commons/d/d2/Concavemirror_raydiagram_2F.svg
- Objects between the center of curvature and the focal point will create real images.--> TRUE: as it can be seen from the ray diagram (2F corresponds to the center of curvature), the image in this case is on the same side of the object, so it is real. </span>https://upload.wikimedia.org/wikipedia/commons/9/91/Concavemirror_raydiagram_2FE.svg
<span>You could easily define it this way. This would be valid. But for most of history it was unclear when a baby was conceived, so it would be silly for someone to say their baby was 9 months old when it was actually born at only 8.5 months. Days of conception similarly would not be a good substitute for birthdays because no one would know them. Then in general it was much easier to mark someone's age as when they came into the world as an independent being, and this tradition is far too entrenched (and simple and easy to handle and universal for people in poor countries etc) to think we would at all gain from now finding exactly the date of conception and counting age from that point.</span>