Write a Chain Rule Formula for the Following Derivative $$\frac { \partial w } { \partial t } \text { for } w = f ( x , y , z ) ; x = g ( r , s ) , y = h ( t ) , z = k ( r , s , t )$$

Multiple Choice

Write a chain rule formula for the following derivative.
- $$\frac { \partial w } { \partial t } \text { for } w = f ( x , y , z ) ; x = g ( r , s ) , y = h ( t ) , z = k ( r , s , t )$$

A) $\frac { \partial w } { \partial t } = \frac { \partial w } { \partial y } \frac { d y } { d t } + \frac { \partial w } { \partial z } \frac { \partial z } { \partial t }$
B) $\frac { \partial w } { \partial t } = \frac { \partial w } { \partial y } + \frac { \partial w } { \partial z }$
C) $\frac { \partial w } { \partial t } = \frac { d y } { d t } + \frac { \partial z } { \partial t }$
D) $\frac { \partial w } { \partial t } = \frac { \partial w } { \partial z } \frac { \partial z } { \partial t }$