Which of the following is a limit of science?
the technology or tools available to test scientific claims
the number of times an experiment can be repeated
the total number of scientists in a field, like physics or chemistry
the use of critical thinking and evidence to study phenomena

The use of critical thinking and evidence to study phenomena

Explanation:

Science relies a whole lot on experimentation and observation. To make the best methodical and scientific judgement, critical and logical thinking is core to the field of science. But, not all phenomena can  be explained or analyzed this way. Some phenomena can not be easily tested, observed and explained. One example is the belief systems, science cannot really explain to any reasonable extent the assertion of most belief systems.