In the Zone

Daniel and his friend Alex were hanging out after school and playing basketball. Daniel hated playing with Alex because Alex felt the need to trash talk during the game, telling Daniel what a lousy player Daniel was. The thing that bothered him even more than that was the way Alex would talk about how much better he was than Daniel.
After beating him in three straight games, Alex decided to call it a day.
"I'm tired of beating you," Alex said to Daniel. "It's not even funny anymore."
"Shut up," Daniel responded.
Just then, David and his friends took the court. David played forward for the school's varsity squad. He was two years older than Daniel, but they used to be neighbors when they were in middle school. As good as Alex was at basketball, David was better. David even tried to give Daniel tips. "Don't listen to the talk," he once told Daniel. "Just block it out and focus. When you get in a zone, nothing else around you matters."
Daniel waved at David, who waved back. The boys stayed and watched David and his friends play for a few minutes before Alex got bored.
"This is boring; let's go," Alex said.
"You just know you couldn't keep up with them if you tried," Daniel responded.
"I'm going. Are you coming?" Alex said as he began to walk away.
Daniel followed close behind as the two walked home. They passed the park, the school, and Belkin's Gorge. As they made their way around Belkin's Gorge, something caught their eyes. There looked to be a man stranded down below. He was wearing a suit and crawling around, but it looked like some of the construction in the gorge had fallen on him.
"I think that guy fell in!" cried Alex.
"We have to do something," responded Daniel.
"I can go for help. I run faster. You should stay up here. I don't think you could make it down there on your own," Alex said.
"I can make it," replied Daniel.
"Just wait here. Flag down a car if you see one. I won't be long," Alex said and scurried off for help.
The man in the gorge rolled onto his back to see Daniel.
"Help!" cried the man. "I think I've broken my leg. This rock has me trapped!"
Daniel was frazzled. He wanted to help, but he had Alex's words ringing in his ears—I don't think you could make it down there on your own. Just then, he also heard David's voice—Just block it out and focus. When you get in a zone, nothing else around you matters. The man's voice below began to get fainter. Daniel focused and started to climb down the edge of the gorge.
"Hang on," he said. "Help is on the way."
What piece of dialogue from the passage reveals that Daniel wants to show he can do something Alex thinks Daniel cannot do?
A.
I won't be long."
B.
"I can make it."
C.
"Are you coming?"
D.
"Just wait here."

B. "I can make it."