ANSWER
will produce a slope field with rows of parallel tangents
EXPLANATION
A differential equation that is a function of y only does not depend on x, i.e. of the form dy/dx = f(y), where f is a function.
Therefore, the slope field will be independent of the horizontal position. This means that there will be rows where the slopes will be of the same rise/run ratio. When two slopes are the same, they are said to be parallel.
