Question

the ribs are a set of twelve paired bones which form the protective ‘cage’ of the thorax. which of the following are considered as atypical rib.
3rd
8th
9th
10th
none of the above

Explanation:

Atypical ribs are the 1st, 2nd, 11th, and 12th ribs (and sometimes 10th in some classifications). The 10th rib can be considered atypical as it has a single facet on its head (unlike typical ribs which have two) and other atypical features. Among the options, the 10th rib is an atypical rib.

Answer:

10th (the option with "10th")