Answer:
Only the coast
redwood and the giant
sequoia are clearly big enough.
If twofeet "walls" are
enough to hold up the tree around a sixfoot wide car,
then the black willow, the coast Douglas fir, the sugar
pine, and the white oak are big enough as well. 

Complete Solution:
To find the diameter of a circle
when you know the circumference, you divide the circumference
by (pi,
about 3.14). For example, the black willow has a girth
of 400 inches and since 400 ÷ 3.14 is about 127, the
black willow is about 127 inches wide, enough for a car
to drive through and still leave at least 2 feet on each
side.
Tree 
Girth
(4.5 ft above ground in inches) 
Diameter
(girth ÷ ) 
Height
(in feet) 
American
Beech 
279 
89 
115 
Black
Willow 
400 
127 
76 
Coast
Douglas Fir 
438 
139 
329 
Coast
Redwood 
867 
276 
313 
Giant
Sequoia 
998 
318 
275 
Loblolly
Pine 
188 
60 
148 
Pinyon
Pine 
213 
68 
69 
Sugar
Maple 
274 
87 
65 
Sugar
Pine 
442 
141 
232 
White
Oak 
382 
122 
96 

