Final answer:
Quasi-experimental studies have the strength of control over variables but are limited in establishing causation due to the lack of random assignment, which is critical in true experiments for attributing differences to the independent variable. The correct option is B.
Step-by-step explanation:
In the context of quasi-experimental studies, one of the potential combinations of strengths and weaknesses is: Strengths: Control over variables; Weaknesses: Difficulty establishing causation.
This is because while quasi-experiments allow for some manipulation of variables and often include a control group or condition, the lack of random assignment limits the ability to firmly establish causal relationships between variables.
These types of studies often fall between true experiments and observational studies in terms of control over variables.
Experimental controls are critical in experimental design as they allow researchers to focus on the effects of the independent variable by minimizing the impact of other, confounding variables.
Random assignment is also key in reducing the influence of lurking variables, so that any observed differences can be attributed to the manipulation of the independent variable with greater confidence. The correct option is B.