The answer is $(B).$

$2.$ The modulus of elasticity is

$E_c=33w_c^{1\mathrm{.}5}\sqrt[\phantom{2}]{f_c^{\text{'}}}$

$=(33)(145\frac{lbf}{f{t}^3}{)}^{1\mathrm{.}5}\sqrt[\phantom{2}]{3000\frac{lbf}{i{n}^2}}$

$=3\mathrm{.}16{10}^6,(3\mathrm{.}2{10}^6)$

Note that this equation is not dimensionally consistent. The answer is $($D$).$

What modulus of elasticity is predicted by ACI $318$ for normal weight concrete with a compressive strength of $3000lb\frac{f}{i}{n}^2?$

$($A$)0\mathrm{.}26{10}^6$

$($B$)1\mathrm{.}9{10}^6$

$($C$)2\mathrm{.}8{10}^6$

$($D$)3\mathrm{.}2{10}^6$

Sorry it wouldnt let me add both pictures at the same time so the first picture is the solution by im wondering how they got Wc