Final answer:
A lye solution has the highest pH and is considered a base, making it the most basic among the options provided, which include acidic substances like orange juice and sulfuric acid.
Step-by-step explanation:
The substance with the highest pH among the options given is D: a lye solution. pH is a measure of how acidic or basic a substance is. Substances with a pH lower than 7 are considered acidic, while those with a pH higher than 7 are considered basic. Orange juice (pH ~4) and rain (which can have a slightly acidic pH due to dissolved CO2 and other pollutants) are both acidic. A sulfuric acid solution is also highly acidic. On the other hand, a lye solution, which is a common name for a strong base such as sodium hydroxide (NaOH), typically has a very high pH, around 13.5 to 14.