Which of the following would be considered databases? Explain your reasoning.

a$)$ z dictionary

b$)$ stock$-$market listings

c$)$ a catalogue of automobile specifications and prices

d$)$ credit card records of customers' spending habits

e$)$ an essay on Shakespeare's Macbeth

f$)$ a teacher's mark book

g$)$ the Guinness World Records book

h$)$ a list of books on your bookshelf $x$ can't be access easily by eN