The following table was presented in an article summarizing a study to compare a new drug to a standard drug and to a placebo.

Characteristic	New Drug	Standard Drug	Placebo	p
Age, years	45.2 (4.8)	44.9 (5.1)	42.8 (4.3)	0.5746
%Female	51%	55%	57%	0.1635
Annual income, $000s	59.5 (14.3)	63.8 (16.9)	58.2(13.6)	0.4635
% with insurance	87%	65%	82%	0.0352
Disease Stage	0.0261
I	35%	18%	33%
II	42%	37%	47%
III	23%	51%	20%

Which, if any, baseline characteristics are significantly different (at least 0.05 level of significance) between treatment groups?

a. Disease stage

b. Annual Income

c. % with insurance

d. age

e. a and c

f. b and d