\text{(B)}
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find the curve defined by the equation
\[r = \cos \theta + \sin \theta.\](A) Line
(B) Circle
(C) Parabola
(D) Ellipse
(E) Hyperbola

Enter the letter of the correct option.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\text{(B)}
Find the curve defined by the equation
\[r = \cos \theta + \sin \theta.\](A) Line
(B) Circle
(C) Parabola
(D) Ellipse
(E) Hyperbola

Enter the letter of the correct option.
train