As I laid in bed last night , I started to think about what buddy boy 's arms looked like . At first , I could n't conjure up the memory . As I thought about it though , there they were . Strong .

OPT: (a). Because they were told about it . (b). Because of how much they can lift . (c). Because they lifted her up . (d). Because of big muscles .
Q: What may be the reason for knowing the arms are strong ?
(d).