Which statement is correct regarding transaction variants?

A transaction variant is designed to customize the user interface of SAP transactions by allowing specific settings that streamline the user experience. When it comes to inputting default values into data fields, transaction variants excel in this aspect. They enable users to pre-fill certain fields with default values, which can enhance efficiency and accuracy during data entry. This capability is particularly useful in environments where specific, frequently-used settings, such as customer details or standard pricing conditions, can be pre-defined to minimize repetitive data entry.

In contrast, while other statements refer to functionalities related to transaction variants, they do not accurately reflect their core capabilities. For instance, hiding fields typically pertains to field selection rather than transaction variants specifically. Additionally, while GUI enhancements and external fields may relate to broader customization options within SAP, these aspects do not directly align with the intrinsic functions of transaction variants. Thus, the role of transaction variants in inputting default values stands out as a primary and correct assertion.