The data date is: a. The date all information was entered in the computer.
b. The date the scheduler produces new reports.
c. The date as of which all progress on a project is reported
d. The date actual work took place.

c. The date as of which all progress on a project is reported

Explanation:

In construction scheduling, data date (DD), also known in MS Project as Status Date is used to update the periodic schedule. The data date is usually set at month-end or towards the month-end. It is required that all activities prior to the data date are completed and no work is reported as not completed or in-progress.

Appropriate information on the details of the project and accomplishments should be updated before the data date. After the data date, what follows should be the implementation of the remaining part of the project. The data date is also called the as-of date and time-now date.

i will say b. laboratory technician   and if wrong then sorry