The software team at Sephra Corp. has designed a new product that will reduce the time to detect errors by $50$ percent. In an internal report, the head of the team explains the difference between the new software and the existing software as follows: "A new software for error detection has been developed. Although the previous error detection software was effective, it was not user$-$friendly. In contrast, the new software is simple and does not require training." In this scenario, which of the following coherence techniques are used in the body of the report?

a$.$ Time connectors

b$.$ Similarity connectors

c$.$ Contrast connectors

d$.$ Cause$-$and$-$effect connectors