Roughly 21 million Covid cases were reported to the WHO over the last week, setting a new global record for weekly cases from the rapidly spreading omicron variant, Maria Van Kerkhove, WHOs Covid-19 technical lead, said during a live-streamed Q&A across the groups social media channels. The next Covid-19 variant (NV) that will rise to world attention will be more contagious than omicron, but the real question scientists need to answer is whether or not it will be more deadly, World Health Organization officials said on Jan 25, 2022. Recently, around 34 suspicious samples were collected by Johns Hopkins experts, and the results collected (categorized as New Variant: NV and Omicron: O) after performing tests in the laboratory are captured in the file sub-variant.xlsx. As Omicron infection generally causes less severe disease than infection with prior variants, in this case, consider the Omicron variant as the class of interest. Note: The dataset provides the Probability of New Variant (NV) from the testing laboratory, not the Probability of Omicron (O) from the testing laboratory. a. Calculate the sensitivity and specificity with 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1 as decision threshold probability (cutoff value) respectfully. Plot the result and use the plot to recommend the optimal cutoff value to balance sensitivity and specificity. (Show the axis titles and chart title) b. Calculate the Matthews correlation coefficient (MCC) and F-score with a default threshold of 0.5 and the optimal cutoff from the above question. Discuss your findings. c. When do you use MCC and F-score as measures for evaluation? Which measure do you think is advised to use here and why?