Which of the following is an effective tool to observe trends and results over a specified period of time?

Agree with Mr  Muhammad Farooq

B. Run chart

............B. Run chart...........

B. Run chart is the most suitable answer

option c .....................

I think c is the suitable answer

Run Chart,

Thanks for invite

The answer is:

C. Control chart

I think both Run chart and Control chart are right, but Control chart scores over run chart since it establishes a result where a process is stable or not whereas Run chart cannot tell the same.

Hence Option C Control chart should be the apt answer 

I think Option C. Control chart

A run chart is a line graph that shows data points over time. Run charts are helpful in identifying trends and predicting future performance.