Mary was challenged by her friend, kate, to memorize 15 letters, c, i, a, c, b, s, a, b, c, f, b, i, i, r, and s, in the same order, within half a minute. mary arranged these alphabets into groups: cia, cbs, abc, fbi, and irs. this made it easier for her to meet kate’s challenge. in this scenario, mary has used the tactic of
(a) self-reference (learned by own experience)
(b) chunking
(c) rehearsal (looking over it a lot)
(d) priming

The right answer is option B „chunking”

Explanation:

Chunking is the process in which we take separate pieces of information, named as chunks, and we group them in bigger items because this way the information given will be easier to retain, as well as we can remember more. This is because our short-term memory just allows us to keep in mind, according to various studies, between four or nine chunks of information, so for Mary will be easier to retain 5 groups of 3 letters than 15 individual letters.  

answer; ///approx///5,000 miles;

answer; (b) knowledge based summaries of our beliefs and feeling about the self in particular domains;