A small scale citrus fruit farming operation in Florida consists of 50 acres. The farm is subdivided into 1/2 acre subplots (for a total of 100 subplats). After an unexpected frost, the farmer wants to assess any damage. To do this, the farmer randomly selects 15 of the subplots and observes every tree in the selected subplots for damage. Which of the following best describes this sampling? Options: A.) stratified sample B.) systematic sample C.) clister sample D.) simple random sample