Read the following context and choose the best option to answer the question.
Context: " I thought I 'd make sure you were feeling all right . " Sanzo 's eyes narrowed in a frown . Hakkai 's brow furrowed slightly as he continued , watching Sanzo intently .
Question: What is the reason Hakkai 's brow furrowed ?
Options: 
A. None of the above choices .
B. He wanted to pretend to look in a different direction .
C. Hakkai was n't trusting Sanzo .
D. The eyes and brow furrowed at each other in a battle of " who can stare the longest " .


C