Chapter 18, Problem 5RA

Which of these statements about trypsin is true?

$\begin{array}{l}\text{a}\text{. Trypsin is derived from trypsinogen by the digestiveaction or pepsin}\text{.}\hfill \\ \text{b}\text{. Active trypsin is secreted into the pancreatic acini}\text{.}\hfill \\ \text{c}\text{. Trypsin is produced in the crypts }\left(\text{of Lieberkuhn}\right)\text{.}\hfill \\ \text{d}\text{. Trypsinogen is converted to trypsin by the brush border enzyme enterokinase}\text{.}\hfill \end{array}$