Switch.

Multi-tasking is not as effective as we might think.  Cognitive load is impaired by the effort needed to concentrate on one thing, let alone concentrating on more than one thing.  We now know that both things suffer.

The other hidden cost is the time needed to switch between tasks.  It is underestimated in the time management and productivity hacks.  There is little recognition of switching time. 

The effort to switch banks, or to switch health insurance funds, perhaps doesn’t directly compare to switching between responding to emails, to knuckling down and writing a technical report.  Not really, but maybe almost.