How do you get from 1-phenyl-1-butanone (m/z = 148) to the phenyl cation (m/z = 77) on a mass spectrum? I know it's two fragmentations, but I'm not sure where

Comparison of specific functional group diagnostic peaks (C=O carboxylic acid, C-H, O-H carboxylic acid, O-H phenol, C=C) between Literature and Experimental spectra.

Drag the appropriate labels to their respective targets. Note: not all labels can be used. oC(sp) – C(sp²) σC(sp) - C(sp) C(sp²) - C(sp²) oC (sp) - H(s) σC(sp²) - H(s) TС(px) - C(px) TС(Py) — С(Py) TС(P₂) - C(pz) H H

The leaves of the Brazilian Tree Senna multijunga contain a number of pryidine alkaloids that inhibit acetylcholinterinase. Two recentyl isolated isomeric compounds have the strcture have the strcture shown below. (NOTE: M=293) Use the mass spectral data provided to determine the precise location of the hydroxyl group in each isomer.  Isomer A: EI-MS, m/z(rel. int): 222(20), 150(10), 136(25), 123(100) Isomer B:EI-MS, m/z(re;. int): 236(20), 150(10), 136(25), 123(100)