You are asked to study the causal effect of hours spent on employee trainingâ (measured in hours per worker perâ week) in a manufacturing plant on the productivity of its workersâ (output per worker perâ hour). Required:a. Choose a random group of employees to receive ten hours per week in additional training for a period of four weeks.â Then, estimate the difference in productivity between workers who received the additional training and those that did not. Option best describes this statement. b. Data on hours spent on training a group of ten different employees in a certain day. Option best describes this statement. c. Data on hours spent on training the same employee for seven consecutive days. Option best describes this d. Data on hours spent training for a group of ten individual employees for seven consecutive days. Option best describes this statement. 1. an observational time series data set. 2. an observational cross â sectional data set. 3. an ideal randomized controlled experiment. 4. an observational panel data set.