Which experimental design decision would most likely produce invalid and unreliable results? having more than one controlled variable
having only one control group
having more than one independent variable
having only one experimental group

Explanation:

The independent variable determines the value that needs to be calculated or the decision that needs to be made from the observations of the experiment. Hence, experimental design decision would most likely produce invalid and unreliable results when having more than one independent variable.

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."

answer denitrification;