Which sentence contains a misplaced modifier?

a.
mr. swanson folded up the tent and packed it away in a sack.

b.
the swansons pulled on their backpacks and walked to the trailhead.

c.
the boys chattered about their fishing trip inside their tent.

d.
after much anticipation, the swansons began their five-mile hike up the mountain.

Read the excerpt from "mother tongue." lately, i’ve been giving more thought to the kind of english my mother speaks. like others, i have described it to people as “broken” or “fractured” english. but i wince when i say that. it has always bothered me that i can think of no other way to describe it other than “broken,” as if it were damaged and needed to be fixed, as if it lacked a certain wholeness and soundness. what best supports the inference that tan believes nonstandard english is no less valid than standard english? tan spends a lot of time thinking about her mother’s “fractured” english. tan has trouble thinking of descriptive words when she is writing. tan’s american education makes it difficult for her to understand her mother. tan winces when she describes her mother’s english as “broken.”