Answer:
b. 10,000.
Step-by-step explanation:
The number of units completed in April is given by the number of units on April 1st (3,000) added to the number of units started during April (11,000) minus the number of units still in production on April 30th (4,000):
![\begin{array}{ccc}Starting\ n^o\ of\ units&3,000\\Units\ started\ in\ April&11,000\\Units\ not\ completed\ in\ April&(4,000)\\Units\ completed\ in\ April&10,000\end{array}](https://img.qammunity.org/2020/formulas/business/college/fr2x95iggz0xt2vhskebv68017lv0u08nb.png)
10,000 units were completed during April.