The following chart displays $\_\_\_\_\_\_.$

This chart shows data spanning $25$ days and measures in minutes each day. A dashed horizontal red line is labeled LCL and is at the $10\mathrm{.}6$ level, while another dashed red line labeled UCL is at the $41\mathrm{.}9$ level. Each day shows a pinpoint of minutes for the day and a solid line connects them, creating a jagged line. The point on day $10$ reaches $55,$ which is above all others and the upper dotted red line.

a$.$ actual sales

b$.$ high and low stock prices

c$.$ control limits

d$.$ production timelines