Two Part Analysis GMAT - Question 3

The Two-Part Analysis question type is part of the GMAT exam.
In this type of question, you're presented with a problem and two associated questions that you must answer. Both of these questions relate to the same data or information provided, but they usually require different aspects or parts of the data.
The format is different from other question types on the GMAT. Rather than multiple choice with one correct answer, there is a table with two columns and five rows, making a total of ten answer choices. The task is to select one answer from each column. The correct answer could be any combination of a row.
Supervisor’s memo: At the present rate of manufacture we will not have the 1,200 circuit boards assembled in time to ship them to the customer. We currently have 10 workers, working 8 hours a day, assembling the boards, and to date they’ve assembled 400. In order to finish the customer’s order in time, I’ll need to have each of the workers work an additional 2 hours for each of the 10 work days between now and the deadline.
One can determine the hourly rate at which each worker assembled circuit boards up to the date of the supervisor’s memo by dividing __1__ circuit boards by the product of __2__ worker-hours and the number of days since the workers began assembling the circuit boards.
Select "Circuit boards" for the option that fills the blank labeled 1 in the given statement, and select "Worker-hours" for the option that fills the blank labeled 2 in the given statement to create the most accurate statement on the basis of the information provided. Make only two selections, one in each column.