In terms of the leads "looking at" the hea walls, which of the following is an odd one out?
Leads II, III, and aVF are called "inferior leads". These leads have their positive (or exploring) electrode on the foot. These 3 leads look to the hea from below; i.e., they are directly looking at the inferior wall of the hea. Any ECG changes in these 3 leads will be reflective of pathology of the inferior wall (e.g., inferior wall MI). avL looks at the hea from left side, hence it is the odd one out.
Lead II
Lead III
Lead aVL
Lead aVF
ECG