Chapter 13, Problem 8RA

The cells that normally have the fastest rate of spontaneous diastolic depolarization are located in

$\begin{array}{l}\text{a}\text{. the SA node}\text{.}\hfill \\ \text{b}\text{. the AV node}\text{.}\hfill \\ \text{c}\text{. the bundle of His}\text{.}\hfill \\ \text{d}\text{. the Purkinje fibers}\text{.}\hfill \end{array}$