Create a random forest ensemble classification tree model using the accompanying data set (predictor variables: x₁ to x₅; target: y). Select two predictor variables randomly to construct each weak learner. 

a. What are the overall accuracy rate, sensitivity, and specificity of the model on the validation data? 

b. What is the lift value of the leftmost bar of the decile-wise lift chart? 

c. Which is the most important predictor variable?

d. Score a new record with the following values: x₁ = 52.8, x₂ = 230.50, x₃ = 1, x₄ = 144, x₅ = 6.23. How would the record be classified using the random forest ensemble model? What is the probability of the record belonging to Class 1?