The remaining battery percentage, $p$, of a smartphone is affected by the hours of video playback, $h$. Which variable is the dependent variable in this situation?

The remaining battery percentage, $p$.

The hours of video playback, $h$.

A chef notes the final temperature of a soup, $T$, depends on how many minutes it simmers, $m$. A student argues that $m$ is dependent because the chef chooses $m$ based on the target $T$. Which statement is true?

The simmering time, $m$, is the dependent variable because the chef chooses it.

The soup's temperature, $T$, is the independent variable because it's the goal.

The simmering time, $m$, is the independent variable because it causes the temperature to change.

Both $T$ and $m$ are independent variables.