To solve this problem, we need to understand the type of selection represented by artificial selection for higher milk yield in cows.$\newline \bullet$Directional Selection:$\newline$ - Directional selection occurs when individuals with traits on one extreme of a phenotypic range are favored over others, causing a shift in the population's trait distribution.$\newline$ - In this case, selecting cows for higher milk yield pushes the mean milk production in one direction, towards higher yields.$\newline$ - This matches with the concept of directional selection.$\newline \bullet$Disruptive Selection:$\newline$ - Disruptive selection favors individuals at both extremes of a trait distribution, potentially leading to a split in the population.$\newline$ - This does not apply here, as the selection is not favoring both low and high milk yields.$\newline \bullet$Stabilizing Selection:$\newline$ - Stabilizing selection favors the average individuals in a population and reduces variation.$\newline$ - This is not applicable here, as the goal is to increase milk yield, not maintain an average.$\newline$Therefore, the correct answer is Option 1: Directional as it pushes the mean of the character in one direction.