John works in a manufacturing plant where a team of researchers is conducting a study on employee productivity. The researchers are particularly interested in the impact of attention and observation on individual performance. As part of the study, they select a group of workers, including John, and start closely monitoring their work. What phenomenon is likely to be observed in this situation, where the researchers are closely monitoring John and his colleagues? Group of answer choices The Halo Effect The Hawthorne Effect The Dunning-Kruger Effect The Pygmalion Effect