the resultant force and resultant couple are always zero

the resultant force is zero but resultant couple is not zero

the resultant force is zero but resultant couple may not be zero

the resultant force and resultant couple both may not be zero

trusses only

beam only

rigid frames only

any type of structure

mechanically formed sedimentary rock

igneous rock

chemically precipitated sedimentary rock

metamorphic rock

sand stone

lime stone

shale

gypsum

only (iii)

both (i) and (iii)

both (ii) and (iii)

all (i), (ii) and (iii)