Question:
Which employer did Allison Littlejohn work for in Apr, 2016?

Context:
 Allison Littlejohn works for University of Glasgow from Apr, 2019 to Dec, 2019. 
 Allison Littlejohn works for The Open University from Jan, 2015 to Mar, 2019. 
 Allison Littlejohn works for University College London from Dec, 2019 to Dec, 2022.

Answer:
The Open University