When did Catholicism experience its first noticeable decline in Australia?

The correct choice reflects the significant decline of Catholicism in Australia, particularly noted in the 1996 census data. This period marked a turning point where a noticeable decrease in the number of individuals identifying as Catholic became evident. Various socio-cultural factors contributed to this decline, including changing attitudes towards religion, increased secularization, and a growing diversity of religious beliefs due to immigration and multiculturalism. This decline was not immediately observable until the 1996 data was released, highlighting a shift from the generally stable or increasing trends in Catholic affiliation observed in prior decades.

In contrast, earlier periods like the 1960s and even the year 1980 did not show the same level of decline; in fact, many religious denominations, including Catholicism, were still experiencing growth or stability due to post-war contexts. Hence, the decline noted in 1996 is seen as the first significant drop in Catholic identification within the Australian population.