Complex sentence: Hawkgirl has urged that Amazon Princess to use the Lasso of Truth on the God of the Underworld to verify this information, however Diana chose not to, possibly because she knew it could be the truth.
Split into simpler sentences: Hawkgirl has urged that Amazon Princess to use the Lasso of Truth on the God of the Underworld to verify this information. However Diana chose not to, possibly because she knew it could be the truth.