"This source of public international law is described as 'evidence of a general practice accepted as law.' This is one of the important source of Public international law". Which of the following source is being discussed here?

International Conventions The general principles of law recognized by civilized nations International Custom Treaties

International Custom

According to Article 38 of its Statute, the International Court of Justice 'whose function is to decide in accordance with international law such disputes as are submitted to it,' has to apply, inter alia, 'international custom.' This source of public international law is described, in the same Article, as 'evidence of a general practice accepted as law.'