1) The elderly ldy continued on her way _____________it was getting dark.

unless as although because when since


2) Precious gobbled her food ______________when she saw the cat coming.

unless as although because when since

In (2), you have included one of the choices, 'when'.

Note, however:
gobble : eat something hurriedly ( and noisily)

Why hurriedly? "…BECAUSE she saw the cat coming (who might try to eat/gobble the food too!)"

What do you think is the answer to (1)?