" That 's why I thought you might be ill . " Sanzo 's frown deepened as he stared at the ground and ran a hand through his hair in distraction . " ... I ' m sorry , " he mumbled , shocking Hakkai and not paying attention at all to what he was saying as he retreated back inside .

Based on the preceding passage, choose your answer for question What may be the reason he retreated back insde ?
Available options:
(A). He was afraid he was going to get attacked .;
(B). He needed to use the bathroom that very moment .;
(C). He was hungry and wanted something to eat .;
(D). None of the above choices .;
The answer is:
(D).