Please answer using Rstudio

The famous data set iris which gives the measurements in centimeters of the variables sepal length and width and petal length and width, respectively, for 50 flowers from each of 3 species of iris is available in R. Type iris directly to see what it looks like. 1. List the variable names of the data set iris. What are the classes for each variable? 2. Select the subset of the data frame whose Species are setosa and report the median (use function median) of 'Sepal. Width' of the selected subset. 3. Select the subset of the data frame whose Species are either versicolor or virginica and report the average of 'Petal.width' of the selected subset. 4. Select the subset of the data frame whose Sepal. Length are greater than 4.5 but less than 6.0. Report the variance (use function var) of 'Sepal.Length' of the selected subset. 5. Combine the data frames you got in part 2 and part 4 to one data frame. Report the number of observations in this data frame. 6. There are some duplicated observations in the data frame you obtained in part 5. Use help (unique) to learn the usage of the function unique and then utilize it to make the data frame you obtained in part 5 doesn't contain any duplicated observations. Report the number of observations in this data frame