Does the descriptor musalsal alone establish a hadith as ṣaḥīḥ?

Muttafiq-Muftariq, Muhmal, Narrator Denial, and Musalsal

• Yes, since all narrators must be trustworthy
• No, the independent criteria of authenticity must still be checked
• Yes, if there are three narrators
• No, because every musalsal report is weak