[John 6: 53-56] So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink His blood, you have no life in yourselves. He who eats My flesh and drinks My blood has eternal life, and I will raise him up on the last day. For My flesh is true food, and My blood is true drink. He who eats My flesh and drinks My blood abides in Me, and I in him."
We see that those disciples He tested were some of the seventy He sent out and who returned with great reports. The eating of His flesh and drinking of His blood was definitely a thought provoking statement, but instead of asking questions some of His disciples left Jesus while saying , “This is a difficult statement; who can listen to it?”  As a result of this many of His disciples withdrew and were not walking with Him anymore.
Jesus turned to His twelve and asked, [67-68] “You do not want to go away also, do you?” Simon Peter answered Him, “Lord, to whom shall we go? You have words of eternal life."
The other disciples did not ask any question, which would signify their seeking of the Truth, but Simon Peter answered Jesus' question with a question and with a statement of confidence.