Final answer:
The word 'vacancy' means an opening, and the closest option to it is 'position'. A 'hypothesis' is similar in meaning to a 'suggestion'. The visual perception principle describing smooth lines is the law of 'good continuation'.
Step-by-step explanation:
The word "vacancy" refers to an opening or available position. When associating the word "vacancy" with one of the given options, the correct match would be a) position because it signifies a job or role that is unoccupied and available for someone to fill. This is in contrast to closure, obstacle, and contract, none of which suggest an available opening.
For the question about which word is closest in meaning to "hypothesis", the closest match would be d) suggestion. A hypothesis is a proposed explanation for a phenomenon, which is a suggestion or a tentative insight that has yet to be tested and confirmed.
In terms of visual perception principles, the law that describes the phenomenon where people tend to see continuous, smooth, or flowing lines instead of choppy or jagged lines is known as the law of b) good continuation.