Answer:
A hint the author gives to help you find a difficult word in a text
That, is the answer i would think
(b) 'They saw a tethered goat with a bright orange stripe across its back' is the first clause and 'they passed a farm' connected with 'as'
Reading something is using your imagination, as to watching is processing your brain to focus on something.
Reading uses your brain in a different process than watching,