a $7-$bit binary word

Select one or more:

a$.$

may be used to encode a text character in the UTF$-8$ code

b$.$

may be used to represent an unsigned integer in range $1.\mathrm{.}128$

c$.$

may be used to encode an integer in $2\text{'}$s complement coding in the range $-64..+63$

d$.$

is sufficient to store any ASCII character code