You chose B as an affirmative sentence
The question is that he doesn't choose either of his two cell phones (as you can see later), and uses either
I. either:
Either
Either
----Shall
I
come
On
Tuesday
or
Wednesday?
----
Either
day
is
OK.
Also (used at the end of a negative sentence instead of too,<
as
well,
also).
He
is
not
a
worker,
I
am
not
either.
either . .or... Either ...... or ...... or ...... or ......
Either
you
or
I
am
right.
Conjugate the subject verb with the "proximity principle".
II. neither
Neither
of
them
knows
me.
neither . .nor... Neither ...... nor ......
He
has
neither
money
nor
time.
It has neither money nor time.
Three.all
All, all (more than three), modifies both countable and uncountable nouns.
All
the
books
are
useful
to
us.
All
knowledge
comes
from
practice.
All is used in conjunction with the negative word not to mean "partial negation", which means "not all ......... ."
I
don't
know
all
of
them.
I don't know all of them.
All
don't
agree
with
you.
=
Not
all
agree
with
you.
Not everyone all agree with you.
Four.both
Both
Both
You
can
take
both
of
them.Both you can take.
When used with a negative word, it means "partial negation".
I
don't
know
both
of
them.
both . . and... Both......
He
can
both
sing
and
dance.