much is the change of length under the load of 25

1-what is the estimated of concrete modulus based on ACI formula, If the conctrete has a compressive strength of 5000 psi ?A. 4.0×10^6 B. 3×10^5 C. 5×10^6 D. 4.6×10^62-solve steel problems 1-3 based on information given below :A steel specimen has a length of 8 inches and a diameter of 0.8 inch. A tensile force was applied. the specimen yeilded at a load of 12.8 kips. the diameter of the specimen becomes 0.78 inch at yield.1- which is the engineering stress at yield :A.6.37 ksi B. 6.53 ksi C. 25.46 ksi D. 26.792- which is the true stress at yield :A.6.37 ksi B. 6.53 ksi C. 25.46 ksi D. 26.793- If the elastic modulus of the steel is 25×10^6 psi, how much is the change of length under the load of 25