All you have to do is count the terms.  If there is
1 term, it's a monomial. If there are 2 terms, it's
a binomial. If there are 3 terms, it is a trinomial.
If there are more than 3 terms, it is just called
a "polynomial".
a.  , 3 terms, so trinomial. 
b.
, 3 terms, so trinomial. 
b.  ,3 terms, so trinomial.  
c.
,3 terms, so trinomial.  
c.  , 2 terms, so binomial. 
d.
, 2 terms, so binomial. 
d.  , 3 terms, so trinomial. 
e.
, 3 terms, so trinomial. 
e.  , 1 term, so monomial. 
f.
, 1 term, so monomial. 
f.  , 3 terms, so trinomial. 
g.
, 3 terms, so trinomial. 
g.  , 4 terms, so polynomial.
h.
, 4 terms, so polynomial.
h.  , 2 terms, so binomial. 
i.
, 2 terms, so binomial. 
i.  , 1 term, so monomial. 
j.
, 1 term, so monomial. 
j.  , 3 terms, so trinomial. 
k.
, 3 terms, so trinomial. 
k.  , 4 terms, so polynomial. 
l.
, 4 terms, so polynomial. 
l.  , 2 terms, so binomial. 
m.
, 2 terms, so binomial. 
m.  , 1 term, so monomial.
n.
, 1 term, so monomial.
n.  , 2 terms, so binomial. 
o.
, 2 terms, so binomial. 
o.  , 3 terms, so trinomial.
Edwin
, 3 terms, so trinomial.
Edwin