The correct option is B Neither
Here, 'neither' is correct because it implies nor the other of two people. Here, 'none' of Peter or John is very tall.
'So' is incorrect because it is used to refer back to something that has already been mentioned.
'Too' is incorrect because it is used before adjectives and adverbs to say that something is more than is good, necessary, possible, etc.
'Short' is incorrect because it implies measuring or covering a small length or distance, or a smaller length or distance than usual.