It depends on your teacher, it should be A. It could be B if that’s what your teacher wants but I would go with A.
Answer:
Null hypothesis: male and female spiders organized in mating pairs don't differ significantly in respect to body length
Alternative hypothesis: male and female spiders organized in mating pairs exhibit significant differences in respect to body length
The application of one statistical test in order to obtain one p-value (probability value) may provide useful evidence to support the alternative hypothesis (or reject it).
The inference procedure uses the information collected from the sample in order to obtain one conclusion. Frequentism is a type of inference procedure that can be used to test a hypothetical test case, which is here represented by male and female spiders organized in mating pairs.
