[A] To check which approval was accepted by whom, go to the Reports module.
[B] Search for "Approval Status Report".
[C] Specify the creation date and click Generate Report.
[D] In the "Select Column" section, make sure that the "Approved by" column is selected. Then you can view the list of approvals and who were they approved by.
[E] Note that the Approved by column will show a blank field in case of pending approvals.