When installing a refrigerator, the cold water line should be connected using tubing that is?

The correct choice for connecting the cold water line when installing a refrigerator is 1/4" OD tubing. This size is standard for the water supply lines that feed into refrigerators, particularly for ice makers and water dispensers. Using 1/4" OD tubing ensures that there is adequate water flow to the refrigerator while preventing any pressure issues that could arise from using either larger or smaller tubing. Moreover, the 1/4" size strikes a balance between flexibility for installation and sufficient capacity to supply the necessary volume of water without excessive strain on the plumbing fixtures. This makes it a preferred choice in plumbing applications for refrigerators.